Via POLITICO's Robin Bravender, the SEIU is lining up behind President Barack Obama early, even as some other unions are balking about doing much — at least at this point — in the 2012 election:

“President Obama fights for working families,” SEIU president Mary Kay Henry told reporters on a conference call announcing the endorsement.

“He shares our vision of a nation that invests in good jobs where everybody pays their fair share and that values health care and public services for everyone in our country and insists on a pathway to citizenship for every immigrant worker. He made working families a priority while other leaders sided with corporations and millionaires.”

Henry said the early endorsement from one of the nation’s biggest and most politically active unions will allow SEIU to mobilize even more voters than it did in 2008.

“We need to have robust discussions in every community in this country about the choices working people face in the November 2012 election, and we intend to use every day between now and then to make the issues clear and to explain what’s at stake and turn out in numbers way beyond what we did in ’08 because there is a lot at stake for our communities,” she said.

Among the uphill climbs Obama is facing is stirring up the base, and to the extent that a union with deep voter-contact experience can help him, it's a plus.